The natural person does not accept the things of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned. The spiritual person judges all things, but is himself to be judged by no one. “For who has understood the mind of the Lord so as to instruct him?” But we have the mind of Christ. 

1 Corinthians 2: 14-16

Paul contrasts the natural person and the spiritual person in the understanding of things revealed by God’s Spirit and so what kind of people make up the church at Corinth? Only In my opinion, the church at Corinth is strikingly similar to many churches in our culture today because they were spiritually active and enthusiastic, but he refers to them as largely immature in their faith as Paul continues into chapter three –

But I, brothers, could not address you as spiritual people, but as people of the flesh, as infants in Christ. I fed you with milk, not solid food, for you were not ready for it. And even now you are not yet ready, for you are still of the flesh.

1 Corinthians 3:13(a)

A mother’s milk is essential to the newborn and the baby, but most would agree that a teenager needs to be weaned, right? The doctrines of sin and salvation are essential, but can you mature based on this kind of diet of basic principles of the faith? I am sure it was a bitter pill to swallow, but the Corinthian church was immature in many areas as a result of their diet and the condition of their lives reflected their condition.

So where are we in our faith? Still infants? No matter where we are, we are encouraged to grow deeper in our spiritual life.